Food hubs are an emerging and increasingly popular approach to reduce obesity trends by improving diet through increased access to nutritious foods. Food hubs offer a wide variety of healthy foods for purchase by both consumers and other food retailers (e.g., corner stores), and typically operate on a value-based business model that prioritizes both economic development and community benefit. Food hubs may be particularly impactful in food desert communities that have limited or no access to traditional food retailers, are low income, and have high rates of obesity. However, there is currently no evidence of the influence of a food hub on dietary behaviors related to preventing and reducing obesity. This study will provide programmatic and policy-relevant evidence to close this gap by taking advantage of a time-sensitive opportunity to evaluate a newly forming food hub that will be established through two independent grants awarded to the community (not the research team) in late 2014. The new food hub will open in October 2015, and this rapid response study will provide a chance to collect baseline data prior to opening. The central hypothesis guiding this research is that the food hub will improve both physical and social access to nutritious foods, which will improve diet quality, fruit and vegetable consumption, and caloric intake among people living near the new food hub. Using a quasi-experimental design with repeated measures, changes in diet will be compared between primary food shoppers living in the intervention community receiving the new food hub to those in a matched control community. Dietary changes will be measured at three time points (baseline and 12 and 24 months post food hub) using the Nutrition Data System for Research, the gold standard for assessing 24-hour dietary recalls to examine individual-level changes. At each time point, three dietary recalls will be collected to provide more accurate estimates. The study will examine changes in the three diet outcomes (e.g., diet quality, FV consumption, caloric intake) between residents in the two communities, will assess the extent that psychosocial factors explain these changes, and, among residents in the intervention community, will examine the dose-response relationship between food hub use and changes in diet using objective measures of food hub shopping. Additionally, this research will contribute to the science of food environment interventions to prevent or reduce obesity by assessing the impact of the new food hub on the broader food retail environment. Finally, the study will contribute to the science and practice of implementing food hub interventions by examining how the specific intervention components (such as healthy food incentives, healthy food community organizers, cooking clubs, etc.) are implemented and received by the community as well as intended and unintended consequences. Findings will provide evidence about the extent to which food hub interventions contribute to changes in diet among people living in low-income, urban communities, and will offer guidance for reducing obesity trends and inequities.